I have 4 routers in media-shared topology (R1,R2,R3,R4). I use OSPFv2 protocol (IPv4) "04:59:40: %OSPF-5 ADJCHG: Process 1, Nbr 10.2.0.1 on Fa0/1 FROM EXHANGE to FULL, Exchange Done" is repeated in R1,R2,R3. I use Packet Tracer 5, and when I use the timers throttle spf spf-start spf-hold spf-max-wait command (R4(config-router)# timers throttle spf 5 20000 20000)**, OSI finds an error ( Invalid input detected at '^' marker.) in "timers". I have 2 queries: 1. Does Packet Tracer support that command and if it supports it, what is the mistake? 2. Do I need to apply this command on every router? ** I used this command on every router with the same results. Thank you.